Internal combustion turbine



June 16, 1942. w. TRUMPL ER INTERNAL COMBUSTION TURBINE Filed Aug. 25,1939 5 Sheets-Sheet 1 INVENTOR. 71 /AM Z'Pz/MPL 57?.

V ATTORNEY.

June 1-6, 1942. w, TRUMPLER 2,286,940

INTERNAL COMBUSTION TURBINE Filed Aug. 25, 1939 3 Sheets-Sheet 2INVENTOR. MLL/AME Ykunrzae 7 ATT0RNEY.

June 16, 1942. w, T U PL 'R 2,286,940

I INTERNAL COMBUSTION TURBINE Filed Aug. 25, 1939 3 Sheets-Sheet 3 54 45L. 1' I INVENTOR. Vl mz. #1 ME 77?UMPLE/?. WATTORNEY.

Patented June 16,

" 2 i UNITED STATES PATENT OFFICE Y 2,286,940' r INTERNAL COMBUSTIONrunning I William E. Trumpler, Easton, Pa. Application August 25, 1939,Serial No. 291,822

a Claims. (or. 60-41) My invention relates to an internal combustionsubstantially abruptly ends and another operaturbine 01 the typedescribed in my Patent No. tion substantially precipitately begins.2,138,220 granted November 29,1938. Further features including themanner'oi sup- The general object of the invention is to proporting therotor and fan, the utilization of a vide a gas turbine which is simplein design, eco- 5 novel bearing arrangement free from the influnomicalto construct and highly efllcient in its ence of the heating meanswithin the turbine, operation, In achieving these objects, applicant andother advantages in construction and operprovides a compact assembly inwhich a blower ation will be more apparent from the following isoperably combined with a turbine, whereby all detailed description ofone form or the invention in desired volume and at a desired pressure isto be read in connection with the accompanying effectively supplied tothe blades of the rotor drawings inwhich:

of the impeller. Combustion is carried on with- Fig. 1 is a verticalsection ofthe apparatus in the turbine casing and the improved designtaken on the central plane of the ,rotor.,

assures maximum utilization of the products of 2 is a v rtic l se tiontaken at ri h combustion for driving the rotor, the supply of angle tothat of Fig. 1 on the line 22 of Flg. 1. air to the turbine assuringefiective scavengin Fig. 3 is a circular sectionaliview taken'in the ofthe products of combustion in a small intermanner of a development on acylin ric l Pl mediate zone, the remainder of the air supplied throughthe i p blades f e r, and to the turbine being utilized in a compressionof the supply fan and casin or' chafnbers instep, as well as for mixturewith the fuel to protersected on t p anevid d s d omb ti Fig, 4 is adetail view taken endwise showing A feature or the invention resides inthe prothe interpositioning f a plurali y of rotor vanes.

vision of a blower and a turbine rotor mounted In he e o i shown i t aco panyon a common shaft, the blower introducing air ing drawings theouter peripheral e portion of (or other gaseous medium) to becompressed. a rotor I0 is rotata ly received W hin the inner The oint ofintroduction of the air within a peripheral portion f a a r p ss andprimary area is under a pressure sufliciently high tu ine compartment II in such a manner that to overcome the back pressure. plus inertia ofthethe rote!" may rotate freely Within h chainheated gases to cause thegases, at the end of h r The casing or chamber H, which maya turbinedriving step, to be scavenged or driven be made of two halves or partsl2 and I3, havi from the rotor, this action simultaneously ,e feet orbases 14 and I5, respectively, and joined fecting an induction or flowof an added volume on a i n pl n to form the casin h s an of i t t t t bcompressed annular raceway I6 centered on the axis of the A furtherfeature resides in the provision of a rotor a shaped closely to fipeller blades 1 compressed air entrance area in combination llprojecting radially outwardly from he o r with blade formations of therotor whereby a W at peripherally pa d ter a So as to per- I continuityof action takes place-(a) a, turbine mit the rotation of blades l1around the raceaction resulting from the utilization of. the a e inward-p e al p t of the easheated gases or products of combustion, (b) a ingH has an annular p ni g I through which scavenging action for riddingthe products of 40 e o r blades-ll extehdh r t r y be combustion in aquick purging step over a relaprovided with annular'flanges l9 fit ingin the tively small area of the rotor, said ridding action annulargrooves 2010f the casing to lorm a labyleaving substantiall no heatedgases to reduce n h se l-'abetween the two. These annular the efficiencyof compression, and (c) a flow into flanges It o rv as t i ha ing surtherotor, in a relatively smooth curve, of the faces between the rotor l0and the casing II to air to be compressed'and an outward flow from pr vt n ven expan i n. the rotor of such air subsequent to compression. ASthe rotor Ill A further feature i e n t provision of the channelsbetween the blades 11 is rotated a plurality of ai rotor, conformed tothe blade formations of the the centrifugal force (if r ation into adifiusor rotor whereby maximum efficiency is achieved or compressionchamber 21-. This chamber exand smooth power curve obtained, despite thetends about somewhat less than one-half of the provision of a pluralityof steps to be performed circumference of the r or and expands from V bythe single rotor, discharging at the same rate an area 22 closelyapproaching, or nearly in into a commonexhaust, wherein one opera ioncontact with, the t ps of the ad s I to its and. blades n rotate, air inentmnce f r ti t v t and, is thrown outwardly from the blades by vvelocity through channels in sleeve widest part, in which is positioneda burner 23 through which fuel is. supplied and admixed with thecompressed gases.

Air is supplied to the channels between the blades I! through an inletpassage 24 extending in the casing half I2 throughout approximately thelength of the compression chamber 2|. Air is supplied to the passage 24and compressed by the rotor-blades, into the compression chamber 2| and"then passes through the burner 23 where it forms a combustible mixturewith the fuel injected and is burned by a continuous flame. The heatedcombustion gases then enter the expansion nozzle or turbine chamber 25.The combustion gases expand I from the compression pressure attheburner. partly through the nozzle or chamber 25 and or chamber 25 andchannels between the blades I! to the exhaust port 26 in the casing halfl3 and extending throughout approximately the peripheral length of thechamber 25, as indicated in Fig. 1, and overlapping the inlet opening 24as shown in Fig. 3.

Throughout the overlapping parts of the openings 24 and 26 air may passfrom the opening 24 through the channels 21 (Fig. 3) directly from theinlet opening 24 opening 26, as indicated by thearrows, thereby drivingout a large part of the products of combustion before the channels againcome into communication with the compression chamber 2|. In order toincrease the compression pressure in the chamber 25 and to provide ahigher 21 at the overlapping part, air is supplied to the inlet opening24 under partial compression pressure by means of a fan 3| supported ina fan casing 29 attached by flanges and screws 30 to the casing half l2of the compressor-turbine casing. Within the casing 23 there is mounteda fan 3| supported on a shaft 32 which also carries, the rotor Ill. Theshaft 32'is rotatably supported or anti-frictionbearings 33 carried in abearing bracket or support 34 having a flange 35 by which it is boltedto the fan casing 29 with screws 36. Through the above arrangement,therefore, the rotor l in rotating also drives the fan 3|. The fan 3|has a number of blades 31 of the propeller type, four being shown by wayof example, extending radially outward and shaped and positioned todrive and supply air into ing to the inlet opening 24 of thecasing Sinceit is particularly important that the flow of airinto the wheel channelsis initiated at the point where the channels leave the nozzle chamberand move into the intake opening 24, a comparatively small channel 40supplies intake air at a pressure above the normal pressure existing atthe balance of the scavenging and intake. port 4| This is accomplishedby the propeller fan 3| and the unique shape of the fan casing asindicated in Fig. 3. Since a supply passage 38 lead-,-.

the intake opening in the turbine casing extends only over a small partof the total periphery, the discharge from the fan, must be diverted bya scroll nular fan opening under normal discharge conditions. Channel40,

to the outlet or exhaust separated by wall 33 from the rest of thepassage 4|, leads to the edge of the intake passage 24 at theoverlapping side.

The pressure of the rotor wheel itself. As the wheel speeds up. thereaction pressure builds up'. The density of the hot gases, due to theirhigh temperature, is about one-third of that of the incoming air. Theair admitted through channel 40 is at higher pressure than that of thegases at point 5|. This pressure is built up because of the inherentcharacteristics of a effectively initiated and carried out. because thefan at the entrance to channel 40 is practically blanked off with theresult that the pressure at this point is substantially shut plusinstantaneous induction effect which causes a simultaneous ridding ofhot gases and initiation of flow of air for compression with theoverlapping of the two steps held to a minimum.

The propeller type fan is the type by which it is possible with simplemeans to create a pressure considerably above normal at a limitedfraction of the normal discharge volume.

The channels 4| created by the walls and 52 and the vane 42 direct theflow helically toward the rotorior reasons to be explained later.

scavenging, no matter how carefully produced, will never be complete dueto turbulence or uneven flow velocity in the blade channels. Since theflow of the scavenging air does not impart to the rotor as much workasis required to compress the additional amount of air, scavengingconstitutes a loss to the turbine as a whole and,

therefore, it is desirable to keep the total volume This length isclosely proportional to the radial blade length and, therefore, theradial blade length must be kept down below a figure determined byexperiment. It is necessary for good operation that the blade length beless than onethird the radius of the rotor to the blade tips, orone-sixth of the outside diameter of the rotor. Also, the shorter bladeshave less contact surface with the hot gases and therefore transmit lessheat to the incoming air, a condition which is very desirable.

To obtain maximum efliciency of the turbine it is necessary to have notonly high turbine and compressor eificiency, .but also good scavengingwith low power loss. In order to accomplish this purpose it is desirableto change the rate of flow through the rotor very gradually. When theblade channel leaves the turbine segment, the radial inward flow ceasesand the intake port supplies air at a partial pressure. If the flow ofair from the intake in the scavenging area is equal, or nearly equal, tothe volume discharged under turbine operation, little or no change inthe velocity of combustion products will take place at the exit edge ofthe blades. This condition is very desirable, as the exhaust velocity ismaintained over the scavenging section and,

the exit velocity energy can be efiiciently recovered in an exhaustdiffuser.

Since air has a much higher density than the hot exhaust gases, theaxial entrance to the blade channels must be larger than the exit.Otherwise the pressure required to make the cold air enter will beexceeded by the pressure required for exhausting the hot gases from thechannel. The intake to the blade channel, however, is not only dependenton the scavenging operation but must also serve as an efiicient intaketo the compression segment. In order to satisfy both the scavenging andcompressor in- .take conditions, it is necessary to increase the bladeangle 53 (Fig. 4) to an angle not muchsmaller than that which the flatpart of the blade makes with the center line of the rotor (angle 54).edge is limited by the compressor operation which requires forefficiency a lower intake area in each blade channel than the exit area.

To satisfy both conditions it is necessary to give the air approachingthe inlet a tangentially forward flow so that the relative velocity atthe blade entrance is low and nearly axial in direction. This permitsonly low entrance loss and eflicient compression. This arrangement doesnot produce as high a compression pressure, but

The radial height at the entrance with the propeller fan producing partof the compression at very high efiiciency, this objection is fullyoffset.

The combination of the precompression fan,

' preferably of the propeller or turbine type, with a turbinerotorhaving a blade height not over one-third of the rotor radius to decreasethe scavenging volume and an unsymmetrical blade to provide efiiciententrance conditions for both compression and scavenging, makes a veryefflcient combustion turbine arrangement. While each individual elementcontributes some improvement, the best result can only be obtained bythe combination of the three features.

What I claim is:

1. An internal combustion turbine of the character described including arotor having a series of peripherally spaced radially projectingimpeller blades, a casing enclosing said blades, a fan within thecasing, an air inlet area for admitting air from the fan to the rotor, achannel within the area forming a passage leading from an area of highpressure at the outlet of the fan to a point at the rotor where turbineaction ceases and compression action is initiated whereby air from thefan provides a flow of air into the rotor against reaction pressure andinertia existing at said point of introduction, and means for deliveringfrom the fan other air at a lower pressure to an area adjacent saidpoint for entrance into the rotor.

2. An internal combustion turbine of the character described comprisinga casing, a rotor within the casing, a fan within the casing, an inletto the rotor from the fan on one side of the rotor, an outlet from therotor on the opposite side thereof, a plurality of channels fordirecting air from the fan toward the inlet of the rotor, one of saidchannels leading to a point in the rotor where turbine action ceases andcompression action commences, another of said channels directing airfrom the fan to an area beyond the first point wherein compression takesplace, means for supplying products of combustion for driving the rotor,said first channel having its inlet positioned to receive air atrelatively high pressure from the fan for delivery for scavengingproducts of combustion and initiating a flow of air at the point whereturbine action ceases against the reaction pressure and inertia existingat said point, said point being located in an area traversed by therotor wherein the inlet to and outlet from the rotor overlap.

WILLIAM E. 'I'RUMPLER.

